I just need to know if I could have any problems by going too big with the t-body. I want to leave plenty of room for more breathing room if I go speed density and superram. I am undergoing a repower with all the goodies, including afr 190s and 218in. 228ex. custom grind roller cam. I am keeping the MAF and stock plenum and runners (ported of course) with an edelbrock base. But I am hoping to change to the superram and a haltech ecu in less than a year. This car is not a daily driver by the way.... Oh yeah, its an 88 model too

[This message has been edited by MikeC.86Roc (edited November 27, 2000).]

 

I have a 58mm Accel TB (which is so damn big that every time I remove the elbow, then I have to force it back to reinstall it) and with full exhaust, runners, base and all the free mods I did loose at least 20LBS/FT of torque and maybe even some power versus stock; but if you have a superram and plan on putting a cam, the 58mm is probably a better purchase. If you have all those things and go with aftermarket heads, then you definately need the 58mm.
Rick

------------------
'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, and intake pieces
13.51@104.27, but can run better as it is.

New 2100-2300 RPM converter is in. Hoping for 13.30 or better.

 

58mm tb are quite big, I would use it only when you need to. you may install it and not upgrade the rest of the engine to warrant it, get it when you need it.

------------------
88 GTA
L98 350
700R4
3:27 axle
MODS,
Edelbrock TES headers, 2.5" straight pipe, Flowmaster 80 series, K&N filter, Accel 8.8mm wires, Bosch Platinum plugs, Wells cap and rotor button, Wells ignition module, MAF screens removed, Hypertech TB air foil, Thermomaster stage II chip, 180* Powerstat, Hypertech cool fan switch, B&M shift kit, B&M power clutch pack, B&M servo, GM fuel filter.
Veiw my car at:

http://www.members.tripod.com/~btessier

[This message has been edited by speed88 (edited November 28, 2000).]

 

You know I love how all these people say that a 58mm TB is too Big. I got news for you guys. You will make more HP because the air flow will be less turbulent no matter what mods you have done to your engine. This is an old wise tale that was true when we were running carbuerators becasue the velocity of the air flowing in caused the fuel to mix with the air. This is not true in a port fuel system. Your velocity is made in the stacking of air in the intake Runners not at the Throttle body. No this can affect torque at low RPMs, but not at the upper. I installed one on mine and it woker the thing up like nothing else. youi can check my sig to see my mods. Oh yea you will haft to adjust the IAC(which I haven't done yet) because at Idle a lot more air will be flowing by your TB than normal)

------------------
86 Trans Am 355 TPI Rebuilt 700R4 with Corvette servo, modified valve body, and a B&M Torque Converter (2000 rpm stall w/ lock up), 87 350 block bored .30 with new crank, bearings, rings, and magnafluxed rods. Reworked 305 heads with 3-angle valve job. Added in the rebuild was an SLP TPI cam, BBK 58mm Throttle Body,SVO 24# injectors,MSD 6A, Hypertech Power Coil, 1.5 Crane roller tipped rocker arms, SLP Intake Runners and Port matching in upper intake including fully ported plenum, TPIS adjustable fuel pressure regulator @ 46psi, Hooker shorty style headers w/ Thermotech heat wrapping, Custom 3” exhaust with Flowmaster muffler and chrome quad tips, Hypertech Thermomaster Computer chip, K&N open element cone filter on modified MAF per TPIS specs, MSD Wires, removal of A/C hardware and a 1LE firewall cover installed. Also there has been a PST front suspension kit with Hotchkis strut tower brace
http://geocities.com/SunsetStrip/Garage/9548/kyle.html

Kills:
95 Talon TSI, 96 Probe GT, 91 T/A L98, 89 RS, 86 Mustang GT, 88 Mustang LX 5.0, 92 Thunderbird V8. couple or ricers that I think were Civics or Preludes not sure what year, 95 Celica GT-S, 94 Chevy 1/4 ton 350, one of those NASCAR F150's

 

Kyle F
I don't know if you were replying to my post or not, but I speak fact. I lost some good torque and I don't really think I gained any power by installing the 58mm TB. I think that unless you have good flowing aftermarket heads, good size cam, high flowing intake setup and full exhaust of course, you don't really need a 58mm. I honestly don't think that the power gain (if any) cancels out the torque loss on a mild engine like mine, to use an example. The reason I have a 58 mm is because I bought it used for $240, so I went for it, but I would trade it for a 52mm; but then again, I might get me new Al. heads, so I might need it later on.

Rick

------------------
'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, and intake pieces
13.51@104.27, but can run better as it is.

New 2100-2300 RPM converter is in. Hoping for 13.30 or better.

 

By the way Kyle, what's the point on using "reworked 305 heads" on a 350?
Just curious!

 

I've always wondered why no one seems to use the 54 mm TB from AS&M? It seems that it would be the right size for many applications where a 52 is a little small but a 58 might be a little big. Accoring to AS&M, the 54mm is cabable of 900 CFM.

 

I vote for the 52mm TB, especially if the motor is a 305, and even a 350 with alot of NA mods. For a 350 which is forced induced, the 58mm TB is best.

A 52mm TB flows about 750 to 800 cfm, more than enough for most applications.


------------------
'87 L98 TPI IROCZ, AFR190 heads, 3.70 gears, ZZ9 cam, 2400 Art Carr TC, SLP 1 3/4" headers, SLP cat-back, no cat, no AC, no MAF screens, Accel manifold base & SuperRam, Edelbrock double roller timing chain, MSD ext coil & distributor, trans cooler, 52mm TB with airfoil, TB coolant bypass, AFPR(48psi), K&N filters, Hotchkis lowering springs, Car-Pro custom chip, Lay Ind. ram air kit, 265/45R16 Kumho V700 tires.
ET 13.39sec @ 107.21mph
'90 Eagle Talon AWD, no rust thru 9 winters
'99 Camaro SS, red, 6-spd, T-tops, Mcleod clutch, Pro 5.0 shifter, MAF processor, Direct Flow airlid, K&N filter.
313.7Hp & 320.6ft-lbf, ET 13.55sec @ 105.1mph
next mod: 4.10 rear gears

 

I think that a 52mm is the largest you should ever use on a small block. People don't seem to realize that you can flow plenty of air through the stock throttle bodies to supply a very thirsty engine.

For example: GM's new Ramjet 502 big block that makes 510 HP and 550 ft*lbs of torque uses a stock L98 48mm throttle body.

Hmmmm.... if a 48mm throttle body can support a 510 hp big block, then why are we spending almost $400 to put a larger one on our 225-350 hp small blocks?

I would just say buy a good airfoil and be done with it. Our engines don't need a larger throttle body until you're laying down some serious power.

------------------
Black 88 GTA L98
New engine is in!
ZZ4 bottom end, Edelbrock 6085 heads, LT4 HOT cam, GMPP 1.6 RR's, ported stock TPI, SLP 1 3/4" headers, no cat, Dynomax cat-back
E.T.F.A Member #11

 

That might be a way too small for a big block. I bet you change that to 58mm TB and you will see easily 20 HP, if not more as well as torque.

 

Well I had to use the 305 heads because it was cost saving. So I used low compression pistons So I can use a supercharger or NOS later on. I figured why should I wast a few hundred bucks now and redo these heads(which work ok) then spend some money on AFR heads later. This also will include a custom PRom after heads and which ever power adder I choose, and when I get my 3.73 gears. Hey I must be doing something right because with the hypertech chip, 2.77 gears on 235 tires and 305 heads I am in the 13.9's. So I fugure with AFR heads to match my cam, 3.73 gears, a set of drag slicks and a custom prom I see 13.0-13.2s easily. Then I get my power adder, preferably a 150 shot of NOS, yes my bottom end will handle it) I ahould see 12.5-12.8 1/4 times. So the 305 heads are just a way to save some money till I can get exactly what I want

 

I didn't say you are doing anything wrong, but fi you had completely stock 350 heads (except for spring)instead of 305 you would be running 13.50 or better. I have less mods than you have and run 13.51@104 MPH with bone stock 350 heads. I'm assuming this is an engine that you put together and when you did, you only had the 305 heads.

------------------
'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, and intake pieces
13.51@104.27, but can run better as it is.

New 2100-2300 RPM converter is in. Hoping for 13.30 or better.

 

Yes I chose to spend my money on other things at the time because I am going to get a set of AFR heads later when I am ready to supercharge or NOS the thing. This will be after gears. Then after that I will get a custom Prom. The thing is I am in college and Engineering school isn't easy so I dont have the extra money to blow on car parts right now when I have to pay rent ya know.

 

Ok, I should have made it more clear in my original post on my plans for this buildup... This motor is a late model 350, 4 bolt main bored .30 over. Steel crank, H-beam rods, forged lightweight pistons with plasma moly rings and all ARP fasteners, Fully balanced and machined. The custom grind efi Reed cam (in.216 ex.228) is degreed in and hooked to a double roller chain. I am in the process building up the rest.. A set of 58cc milled AFR 190 Aluminum heads, comp pro magnum roller rockers and pushrods, Edelbrock base, streetdampr, MSD, headers, custom Y-exhaust no cat, no smog and a flowmaster. This is most of the guts of it, I am planning on stepping up to a superram and a haltech speed density setup within a year. Now...... is there any difference between a 58mm BBK T.body for 88 model MAF and a later model BBK T.body(speed density?) 58mm? Sorry for the confusion and thanks for the help!

 

F22,If you are serious about trading your 58mm for a 52mm Im for it..plus cash

Daz

 

Daz, you must be on crack brotha!!
The 58mm is more expensive than the 52mm. Where do you live anyway and how we gonna do it (if you stop trippin' about the cash thing)?

------------------
'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, intake pieces and 2100 RPM TQ

*13.40@102.55 MPH* <--- Best New ET
1.90 Sec, Best 60FT
104.23 MPH, Best Trap Speed

 

I live in Toronto,What I meant was me paying. Anyways I can pay for both our shipping if you want a trade..BTW my 52mm has the airfoil in it(good for 1/2 sec on the 1/4)

Daz
Superram 383..

 

An air foil worth a 1/2 sec in the 14 mile? Are you sure.

 

KyleF
= joke

ARe you serious??

Daz

 

nobody better than good ole' daz to brighten our lives

 

58s don't cost but like $20 more than 52mm. I think the main reason more people don't use the AS&M 54mm is that they want what...$500?????? All you have to do is read those track results from car craft to see what a MISTAKE it is to bolt on a 58mm to a stock tpi setup. Unless you are running a stroker w/ a vortech or something you don't need a 58....52 is plenty.



------------------
87 IROC-Z, 5.7, auto, 3.27, leather, !cat, Holley fpr, K&N'S, SLP 1-3/4" Jet-Hot coated headers, SLP .218/.224 .495/.502 cam, Comp 1.5 roller tip rockers, $uperPITAram, Edelbrock lower intake, Holley 52mm tb, Dynomax\Flowmaster catback. Coming Soon(?)- Fasttrack/Accell DFI

1989 Pontiac 20th Anniversary Turbo Trans Am - 161,000 miles, !cat, 9" K&N

 

Somebody please respond to my 2nd post instead of turning this into a classified ad...

 

The 85-88 TPI plenums have a hole between the two throttle bores near the bottom. This hole is for the IAC idle air passage. The 89-91 L98 plenum does not have the hole. A throttle body intended for the 89-91 TPI will also work on 85-88's but a throttle body intended for 85-88's doesn't work on 89-91's unless you drill a whole in the plenum. I would geuss BBK consolidated parts and supply a 58mm 89-91 style throttle body for all 85-91's. I hope that wasn't to confusing. In short, you should be able to use either style throttle body on an 88.

 

Daz
I don't intend to hurt your feelings, but I'm really affraid of deals done over the net. I know I won't send you mine first and you probably won't send me yours either. What if there is something wrong with either throttle body? Does yours fit my 88 GTA? The one I have is an accel unit which has been in my car for the last 3 years and is in good condition (you don't have to believe me, fo course). As far as shipping, I don't really care because it shouldn't be that much anyway. What Toronto do you live in, Canada or US?

(there is 2 Torontos right?)

 

yup,Toronto,Ontario, Canada..About my TB,I got mine used with the Superram,TFS heads and a bunch of other stuff.THe bores are noticably larger than my stock TB.Its installed in the car right now.The 87 and 88 TB's should be the same..BTW maybe we should take this up via e-mail

e_daz@hotmail.com

Daz

 

another difference between the diff. year model TBs is the throttle arm on the side. later models have a different style.



------------------
87 IROC-Z, 5.7, auto, 3.27, leather, !cat, Holley fpr, K&N'S, SLP 1-3/4" Jet-Hot coated headers, SLP .218/.224 .495/.502 cam, Comp 1.5 roller tip rockers, $uperPITAram, Edelbrock lower intake, Holley 52mm tb, Dynomax\Flowmaster catback. Coming Soon(?)- Fasttrack/Accell DFI

1989 Pontiac 20th Anniversary Turbo Trans Am - 161,000 miles, !cat, 9" K&N

 

MikeC,
The 52mm TB will flow more air than you will ever need for a 355 cu engine. If you had a 383 or were going to supercharge the engine, the 58mm TB might be better (to ensure that the TB is not a bottle neck).

Go with the 52mm TB. end of story

Goodluck on your engine project. Your engine should be a real screamer. With proper tuning and traction, you will be running in the 12s.

------------------
'87 L98 TPI IROCZ, AFR190 heads, 3.70 gears, ZZ9 cam, 2400 Art Carr TC, SLP 1 3/4" headers, SLP cat-back, no cat, no AC, no MAF screens, Accel manifold base & SuperRam, Edelbrock double roller timing chain, MSD ext coil & distributor, trans cooler, 52mm TB with airfoil, TB coolant bypass, AFPR(58psi), K&N filters, Hotchkis lowering springs, Car-Pro custom chip, Lay Ind. ram air kit, 265/45R16 Kumho V700 tires.
ET 13.39sec @ 107.21mph
'90 Eagle Talon AWD, no rust thru 9 winters
'99 Camaro SS, red, 6-spd, T-tops, Mcleod clutch, Pro 5.0 shifter, MAF processor, Direct Flow airlid, K&N filter.
313.7Hp & 320.6ft-lbf, ET 13.55sec @ 105.1mph
next mod: 4.10 rear gears

 

you're saying on my motor:

10.5:1 355
miniram
afr 190's (Ported)
and cc 306 grind

that I won't need a 58mm?

you're on crack!

I think that my motor will need the 58 and so does Tony Christian's crew cheif (building my motor).

------------------

Cody "cyZ28" Young
'84 black on black Z28

355, 5-speed (on the way out. What goes back in, ooohh baby!!)

 

Thanks for all the replies fellas.. All questions answered!!